The present invention relates to the deposition of soluble materials and in particular to the deposition of soluble materials using inkjet technology.
In recent years there has been an increase in the number of products which require, as part of their fabrication process, the deposition of organic or inorganic soluble or dispersible materials such as polymers, dyes, colloid materials and the like on solid surfaces. One example of these products is an organic polymer electroluminescent display device. An organic polymer electroluminescent display device requires the deposition of soluble polymers into predefined patterns on a solid substrate in order to provide the light emitting pixels of the display device. The substrate may, for example, be formed of glass, plastics or of silicon.
In the manufacture of semiconductor display devices, such as light emitting diode (LED) displays, it has been conventional to use photo-lithographic techniques. However, photo-lithographic techniques are relatively complex, time consuming and costly to implement. In addition, photo-lithographic techniques are not readily suitable for use in the fabrication of display devices incorporating soluble organic polymer materials. Concerns relating to the fabrication of the organic polymer pixels have, to some extent, hindered the development of products such as electroluminescent display devices incorporating such materials to act as the light emitting pixel elements. Consequently, it has been proposed to use inkjet technology to deposit the soluble organic polymers in the fabrication of electroluminescent display devices.